Polymerizable esters of alpha-sulfonated fatty acids



POLYMERIZABLE ESTERS OF ALPHA- SULFONATED FATTY ACIDS Raymond G. Bistline, Jr., Philadelphia, William S. Port, Norristown, Alexander J. Stilton, Philadelphia, and James K. Weil, North Wales, Pa., assignors to the United States of America as represented by the Secretary of Agriculture N Drawing. Application June 24, 1955 Serial No. 517,953

6 Claims. (Cl. 260-400) (Granted under Title 35, U. S. Code (1952), sec. 266) hydroxide, .the reaction mixture was refrigerated at 27 0, thus causing .the precipitation of crude sodium allyl.

A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the 1 power to grant sublicenses for such purposes, is hereby I, granted to the Government of the United States of America. I I This invention relates to-monomeric'and polymeric olefinic esters of wsulfona'ted long-chain fatty acids. An object of this invention is to provide novel compositions having improved surface-active, emulsifying and detergent properties. Another object is to provide novel polymers having emulsifying and detergent propertiesand also being useful as water-soluble thickening agents. Other objects will appear hereinafter. v

According to the invention, esters corresponding to the formula ROHOOOCH2GH=CH2 wherein R is an alkyl group of 10 to carbon atoms and M is Na, K, Li, or NH not only have valuable surfaceactive, emulsifying and detergent properties but are readily polymerized to yield polymers havingsimilar properties and, in addition, being useful. as thickeners for a ua: ou's solutions. For example, a mixture containing water,

an oil such as mineral oil, and such a polymer, as for instance polymerized sodium allyl a-sulfopalmitate and polymerized sodium allyl a-sulfostearate, as an emulsifying agent, forms a stable emulsion.

The fatty acids useful in making our esters are the saturated aliphatic acids of 12 to 22 carbon atoms. Those having less than 12 carbon atoms yield esters deficient in surface-active properties while those having more than 22 yield esters have only very limited solubility in water. The optimum balance between the hydrophilic and hydrophobic properties of the esters is obtained when fatty acids of 16 to 18 carbon atoms are used. This is a for tunate circumstance because the saturated fatty acids available in greatest abundance at lowest cost are palmitic and stearic acids. Of course it is to be understood that it is not necessary or desirable to use a single pure is the crude acid or mixture of acids obtainable from the more saturated fractions of lard, tallow, grease, cotacid and that in general the most suitable acid material Patented July 22, 1958 The monomeric allyl esters are readily polymerized by the usual free radical processes, such as warming with an organic peroxide or-a per-salt, irradiation with ultra violet light or by use of a redox catalyst system.

The invention is illustrated by the following examples 7 EXAMPLEI 7 Preparation of allyl a-sulfo-e'sters I A solution of 0.357 mol of .u-sulfopalinitic acid in 500 ml. of allyl alcohol was refluxed, with stirring, for 20 hr; After being cooledTand neutralized with sodium a-sulfopalmitate in yield and of a purity entirely suitable for use in surface-active or detergent compositions. .l

By repeated crystallization of the crude product from methanol, water, and a mixture of methanol and acetone, the pure compound was obtained as a white powder, M. P. 92.293.4 C., and containing 56.9% C, 8.85% H, 5.68% Na and 8.12% S. Its iodine number was 61.1.

The corresponding theoretical values are 57.3, 8.88, 5.77,

8.05 and 63.7, respectively. By using ot-sulfostearic acid instead, of the'ot-sulfopalmitic acid used above, a yield ofcrude sodium allyl oi-sulfostearate was obtained. Repeated recrystallization yielded the pure compound'as a 'whitefpowder,,M. P.,

EXAMPLE II Polymerization of allyl esters The monomeric esters of Example I were polymerized by dissolving 75 g. of monomer and 3.5 g. of potassium persulfate in 700 ml. of water and heating the solution at 70 C. for 8 hr. The progress of the polymerization was evident by increase in viscosity during this period. After 3 hr. of heating the solutions were too viscous to be stirred effectively.

The polymers were precipitated by the addition of 2100 ml. of ethanol, redissolved in water and again precipitated by the addition of 2 volumes of alcohol. After two more reprecipitations the polymers were dried ina vacuum oven and thus obtained as light cream colored powders in yields of about 70%.

Properties of monomeric allyl esters All the monomeric esters were readily soluble in soft, hard or sea water. Solutions containing as much as 20% of ester became very viscous or gelled on standing. Aqueous solutions were highly stable to most metallic ions, such as Ca++, Mg++, Fe++, Ni++, Cu++ and Zn++, and were effective surface-active, foaming and wetting agents having excellent emulsifying and fair detergent properties. The latter were greatly improved by use of conventional builders. In contrast with most esters, and in particular, esters of carboxylic acids not having an u-sulfo group, the esters of this invention were highly stable to hydrolysis in aqueous solution even in the pres- .ence of acid or base. This unexpected property makes these esters of particular value for use as surface-active, wetting and foaming agents, emulsifiers and detergents.

Properties of the polymeric allyl esters The polymeric esters dissolved in soft, hard or sea water to form viscous, thixotropic solutions. Thus, a 2% aqueous solution of polymeric sodium allyl a-sulfopalrnitate at 25 C. had viscosities of 36.8, 23.8, 14.3 and 10.8 poises as measured with a Brookfield synchroelectric viscometer, using a Number 3 spindle at 6, 12, 30 and 60 R. P. M. respectively. Such aqueous solutions were stable to most metallic ions and, like the monomers, were resistant to hydrolysis. The polymers showed little effect on the surface and interfacial tension of water and had only slight foaming and Wetting properties. They showed only fair detergent activity but were extremely effective emulsifying agents.

The emulsifying properties of both the monomers and the polymers were determined by a method of intermittent violent shaking [Briggs, J. Phys. Chem., 24, 120 (1920); Martin and Herman, Trans. Faraday Soc., 37, 25 (1941)]. A stoppered 500 ml. Erlenmeyer flask containing 40 ml. of refined mineral oil and 40 ml. of a 0.1% aqueous solution of the material being tested was manually shaken in 5 violent downward motions and then allowed to stand 1 minute. This was repeated 5 times, after which the emulsion was poured into a 100 ml. graduated cylinder and the time required for the separation of ml. of the aqueous phase was noted. This was a measure of the stability of the emulsion and the effectiveness of the emulsifying agent. Results are shown in the following table.

TABLE I.EMULSIFYING PROPERTIES Polymeric Na allyl a-sulfopalmitate 11,600

Polymeric Na allyl a-sulfostearate 5,550 Na alkylbenzenesulfonate b 180 Polyoxyethylene sorbitan trioleate b 120 a Time for separation of 10 ml. of aqueous phase. Commercial emulsifying agents.

a The other monomeric and polymeric esters of this invention have emulsifying properties similar to those shown in the above table,

We claim: 5 l. A polymer of a compound having the formula wherein R is an alkyl group of 10 to 20 carbon atoms and M is a member of the group consisting of Na, K, Li, and NH 2. Polymerized sodium allyl ct-sulfopalmitate.

3. Polymerized sodium allyl a-sulfostearate.

4. A stable emulsion comprising water, oil and a polymer of a compound having the formula wherein R is an alkyl group of 10 to 20 carbon atoms References Cited in the file of this patent UNITED STATES PATENTS Dean Apr. 17, 1945 Bert et al. Feb. 8, 1949 Henry et al. Nov. 14, 1950 Brod et al. Nov. 14, 1950 OTHER REFERENCES Stirton et al.: J. Am. Oil Chemists Soc. 29, l9820l (1952).

Cheng et al.: 1'. Chinese Chem. Soc., Ser. II, 1, 134-l46 (1954) (cited in Chem. Abs. 49 7287b (1955). 

1. A POLYMER OF A COMPOUND HAVING THE FORMULA
 4. A STABLE EMULION COMPRISING WATER, OIL AND A POLYMER OF A COMPOUND HAVING THE FORMULA 